Many communication devices are powered by a battery. Those battery powered communication devices that minimize power consumption and conserve battery power have a commercial advantage as they help extend the operating time of the communication device. Accordingly, a significant amount of money and effort has been expended to reduce the amount of energy consumed by battery powered devices.
Radiotelephones are one type of battery powered communication device. Radiotelephones operate in a communication system by transmitting and receiving information via channels of the communication system during an active call state. The radiotelephone employs a receiver capable of tuning to any one of a number of different channels to receive information therefrom. The received information comprises synchronization fields and data fields. While waiting to place or receive a call, the radiotelephone monitors the received information in a standby mode. In the standby mode, the radiotelephone remains tuned to one of the channels, and receives and evaluates the synchronization fields and data fields to determine if it should enter an active call state.
It is known to periodically power off the receiver during the standby mode to conserve battery power. Schemes for periodically powering off the receiver are sometimes referred to as "discontinuous receive" schemes. One known discontinuous receive scheme powers off the receiver during portions of data fields that are predicted to be repetitive. Another known scheme powers off the receiver during data fields that are predicted to contain data intended for another receiver. However, such discontinuous receive schemes cannot be employed in communication systems that require reception and evaluation of each data field in its entirety.
Therefore, what is needed is an apparatus and method for discontinuously operating a receiver in a communication system that requires reception and evaluation of data fields in their entirety.